The National Institute for Occupational Safety and Health (NIOSH) has targeted several areas for research. Included in the topic areas of the National Occupational Research Agenda (NORA) is Special Populations at Risk, of which the aging worker is a focus. The present application is targeted to this agenda. The study proposes to test a large group of lead-exposed workers and non-exposed controls who were initially tested 15 to 17 years ago as part of a previously funded project. The prior assessment gathered information on neuropsychological function as well as occupational and medical history, including blood lead levels. These workers are currently age 38 to 77. Several studies have suggested that exposure to lead significantly increases the risk for the development of neurocognitive disorders in later years. There is also a significantly higher odds-ratio for having a diagnosis of neuropsychiatric disorder (e.g., depression) in pensioners who worked at jobs where exposure to lead was commonplace. These earlier studies are limited, however, by several deficiencies. First, they relied on weak markers of exposure - surrogates such as job titles or interviews. Second, in many cases structured and standardized tests of neuropsychiatric function were either not employed or when used, the testing was cursory. Finally, important confounders (e.g., alcohol) were either superficially estimated or ignored. This study proposes to re-evaluate lead-exposed workers and controls (105 subjects in each group) and to stratify workers into three age bands. All subjects will complete a battery of neuropsychological tests and psychiatric measures. In addition, lead exposure will be assessed with X-ray fluorescence to estimate cumulative exposure over the lifetime. Current blood lead levels will also be ascertained. The present application will determine whether long-term occupational lead exposure (as defined by bone lead levels) is associated with greater neuropsychiatric and cognitive morbidity in the aging worker. This is a revision of 1 R01 OH03891-01